"Rx" (℞) is often used as a short form for prescription drug in North America- a contraction of the Latin word "recipe" (an imperative form of "recipere") meaning "take".[1] Prescription drugs are often dispensed together with a monograph (in Europe, a Patient Information Leaflet or PIL) that gives detailed information about the drug.

The use of prescription drugs has been increasing since the 1960s. In the U.S., 88% of older adults (62–85 years) use at least 1 prescription drug, while 36% take at least 5 prescription medicines concurrently.[2]

Many prescriptions issued by health practitioners in Australia are covered by the Pharmaceutical Benefits Scheme, a scheme that provides subsidised prescription drugs to residents of Australia to ensure that all Australians have affordable and reliable access to a wide range of necessary medicines. When purchasing a drug under the PBS the maximum price a consumer pays is the patient co-payment contribution, which, as of January 1, 2014, is A$36.90 for general patients. Those covered by government entitlements (low-income earners, welfare recipients, Health Care Card holders, etc.) and those covered under the Repatriation Pharmaceutical Benefits Scheme (RPBS) have a reduced co-payment, which is $6.00 in 2014. The table below indicates the changes in co-payments over the years. These co-payments are compulsory and cannot be discounted by pharmacies under any circumstances.

Private prescriptions are issued for medicines not covered on the PBS, or being used off-label, for indications other than those covered by the PBS. The patient pays the pharmacy for medicines privately prescribed.

Prescription-only medicines (POM), which can be sold by a pharmacist if prescribed by a prescriber

Pharmacy medicines (P), which may be sold by a pharmacist without prescription

General sales list (GSL) medicines that may be sold without a prescription in any shop

Possession of prescription-only medicines without a prescription is not a criminal offence unless it falls under the Misuse of Drugs Act 1971.[5]

A patient visits a medical practitioner or dentist authorised to prescribe drugs and certain other medical items, such as blood glucose-testing equipment for diabetics. Also, suitably qualified and experienced nurses and pharmacists may be independent prescribers. Both can prescribe all POMs but pharmacists are not allowed to prescribe schedule 1 controlled drugs. District nurses and health visitors have had limited prescribing rights since the mid-nineties, before which prescriptions for dressings and simple medicines would have had to have been signed by a doctor. Once issued, a prescription is taken by the patient to a pharmacy, which dispenses the medicine.

The pharmacy charges the NHS the actual cost of the medicine; the patient pays a set prescription charge in England to the pharmacy. Most of the prescriptions dispensed on the NHS are exempt from charges even in England, as there are many exceptions on grounds such as age and chronic disease, and "season tickets" may be purchased to cover an unlimited amount of medication during a set period. The fee for each item does not depend upon the quantity prescribed by the doctor (which is subject to a maximum of three months' supply), or the cost of the medicine to the NHS, which may vary from a few pence to hundreds of pounds.[9][10]

Outside the NHS, private prescriptions are issued by private medical practitioners, and sometimes under the NHS for medicines not covered by the NHS.[9][10] NHS supply beyond three months' worth is not covered, and must be purchased privately. A patient pays the pharmacy the normal price for medicine prescribed outside the NHS.

Survey results published by Ipsos MORI in 2008 found that around 800,000 people in England were not collecting prescriptions or getting them dispensed due to the cost, a figure which was the same as in 2001.[11]

The Controlled Substances Act (CSA) was enacted into law by the Congress of the United States in 1970. The CSA is the federal U.S. drug policy under which the manufacture, importation, possession, use and distribution of certain substances is regulated. The legislation created five Schedules (classifications), with varying qualifications for a substance to be included in each.

The package insert for a prescription drug contains information about the intended effect of the drug and how it works in the body. It also contains information about side-effects, how a patient should take the drug, and cautions for its use, including warnings about allergies.

As a general rule, over-the-counter drugs (OTC) are used to treat conditions not necessarily requiring care from a healthcare professional and have been proven to meet higher safety standards for self-medication by patients. Often a lower strength of a drug will be approved for OTC use, whereas higher strengths require a prescription to be obtained; a notable case is ibuprofen, which has been widely available as an OTC pain killer since the mid-1980s but is still available by prescription in doses up to four times the OTC dose for use in cases of severe pain not adequately controlled by the lower, OTC strength.

In the United States, the term "prescription drug" is most commonly used, but they are also called Rx-only drugs or legend drugs, after the Federal and State laws that mandate that all such drugs bear a "legend" prohibiting sale without a prescription; though more complex legends have been used, on most original drug packaging today the legend simply states "Rx only". Some of the more controlled medications, such as amphetamines, are usually almost impossible to obtain without a prescription. However, they are often the most abused, especially by college students. Students use them as study aids or "energy boosts" to gain more focus and "drive" to study and complete assignments. The loophole that students use to obtain these drugs without a prescription is still unresolved due to a lack of concrete evidence of if students actually have the attention deficit disorder, ADD, but more extensive studies will be most likely be conducted in the near future to avoid this particular issue. [14].

Although this may seem as beneficial to the student, studies have shown that these types of drugs are extremely addictive. Another setback that has been observed is that, after prolonged use, students may strive towards finishing tasks or irrelevant goals that the drug causes them to feel like they need to finish. [15]. The physiological aspects of these types of drugs on the human body are mainly due to the stimulation of the β-Adrenergic receptor. Symptoms from this stimulation includes increased heart rate, stroke volume, and skeletal muscle blood flow. This drug can be diagnosed and detected in the human body from stomach content, vomit, or positive results found in urine tests that identify illicit drug use.[16]

Also, pharmacies operated by membership clubs, such as Costco and Sam's Club, by law must allow non-members to use their pharmacy services and must charge the same prices as to members.[17]

Physicians may legally prescribe drugs for uses other than those specified in the FDA approval; this is known as off-label use. Drug companies may not promote or market drugs for off-label uses.

Large U.S. retailers that operate pharmacies and pharmacy chains use inexpensive generic drugs as a way to attract customers into stores. Several chains, including Walmart, Kroger (including subsidiaries such as Dillons), Target, and others, offer $4 monthly prescriptions on select generic drugs as a customer draw.[18] Publix Supermarkets, which has pharmacies in many of their stores, offers free prescriptions on a few older but still effective medications to their customers. The maximum supply is for 30 days.

The expiration date, required in several countries, specifies the date up to which the manufacturer guarantees the full potency and safety of a drug. In the United States, expiration dates are determined by regulations established by the FDA.[20] The FDA advises consumers not to use products after their expiration dates.[21]

A study conducted by the U.S. Food and Drug Administration covered over 100 drugs, prescription and over-the-counter. The results showed that about 85% of them were safe and effective as far as 15 years past their expiration date.[medical citation needed] Joel Davis, a former FDA expiration-date compliance chief, said that with a handful of exceptions—notably nitroglycerin, insulin, some liquid antibiotics; outdated tetracyclines can cause Fanconi syndrome—most expired drugs are probably effective.[22]

The American Medical Association (AMA) issued a report and statement on Pharmaceutical Expiration Dates.[23] The Harvard Medical School Family Health Guide notes that, with rare exceptions, "it's true the effectiveness of a drug may decrease over time, but much of the original potency still remains even a decade after the expiration date".[24]

The expiration date is the final day that the manufacturer guarantees the full potency and safety of a medication. Drug expiration dates exist on most medication labels, including prescription, over-the-counter (OTC) and dietary (herbal) supplements. U.S. pharmaceutical manufacturers are required by law to place expiration dates on prescription products prior to marketing. For legal and liability reasons, manufacturers will not make recommendations about the stability of drugs past the original expiration date.[25]